Moving pain management programmes into the digital age: development and evaluation of an online PMP for people with chronic pain.

Introduction: In response to Coronovirus Disease (COVID-19) health care restrictions, the pain management programme delivered group treatment digitally (OPMP). We aimed to: 1) evaluate pain related outcomes of the OPMP, 2) evaluate patient satisfaction and qualitive feedback of the OPMP and 3) compare OPMP outcomes with the pre-pandemic face to face (F2F) PMP outcomes. Methods: Age, gender, pain duration, occupational status, referral information and patient satisfaction data were collected. Pre- and post-treatment pain related outcomes were compared by calculating mean difference, benchmarking with effect size (Cohen's d) and determining clinically significant change (CSC) for OPMP and F2F PMP. Results: Two-hundred and thirty-seven patients provided outcome data, with 60 completing the OPMP and 177 completing the F2F PMP. OPMP patients were 10 years younger than the F2F PMP (44.8 vs 53.3), more were female (6.5:1 vs 2.8:1), more were working (45% vs 27%) and fewer were retired (3% vs 17%). The OPMP showed improvements comparable to the F2F PMP. Large effect size was reported across all outcome domains including objective physical outcomes. Eighty-one percent of OPMP patients were 'extremely likely' to recommend the programme but just over 50% of patients felt F2F would provide greater clinical benefits. Conclusion: The results support that OPMP is effective for carefully selected patients following a multidisciplinary team assessment however more complex cases still require F2F PMP.

Sham controls in device trials for chronic pain - tricky in practice-a review article.

Background: Chronic pain affects one in four people and this figure is likely to increase further in line with an ageing population. Efforts to evaluate nonpharmacological interventions to support this patient population have become a priority for pain research. For device trials, the use of a sham control can add to the scientific validity and quality of a study. However, only a small proportion of pain trials include a sham control, and many are of poor quality. To facilitate the conduct of high-quality trials there is a need for a comprehensive overview to guide researchers within this area. The objective of this review was to synthesise the published data to address this need. Methods: We identified studies that considered the evaluation, design, and conduct of sham-controlled trials in chronic pain by searching MEDLINE, CINAHL and Science Direct to November 2022. Studies that included sufficient content to inform the conduct/design of future research were included. An inductive thematic analysis approach was used to identify themes that require consideration when conducting sham-controlled trials. These are presented as a narrative review. Results: 37 articles were included. Identified themes related to the type of sham device, sham design, bias, study population and ethics. Conclusions: To conduct good quality research the challenges surrounding the use of sham interventions need to be better considered. We highlight salient issues and provide recommendations for the conduct and reporting of sham-controlled device trials in chronic pain.

Complex regional pain syndrome what is the outcome? - a systematic review of the course and impact of CRPS at 12 months from symptom onset and beyond.

BACKGROUND AND OBJECTIVE: To improve CRPS treatment, it is imperative to understand the nature, degree and relative importance of ongoing problems associated with CRPS. The objective of this systematic review was to summarize the published data concerning measures of function and impact including occupational parameters, of CRPS at 12 months from symptom onset and beyond. DATABASES AND DATA TREATMENT: MEDLINE, EmBase and PsychINFO were searched (inception to May 2021). Study cohorts were eligible if they included; adult patients with the primary complaint of CRPS ≥12 months duration, outcomes that reported change in CRPS signs and symptoms, and physical and social function. Prospero registration: CRD42021241785. RESULTS: Twenty-two included studies suggest that pain and motor dysfunction are the most dominant long-term features of CRPS, persisting for 51%-89% of patients at ≥12 months. On average for all patients who had CRPS at baseline, grip strength was found to be reduced by 25%-66%, and range of motion reduced by 20%-25% at ≥12 months. Such losses were associated with physical and social disability. Thirty to forty percent of all patients did not return to work and a further 27%-35% of persons returned to work but required some form of workplace adaptation, although the quality of this data was poor. Quality assessment highlighted limitations in the literature, such as high attrition bias and variations in diagnostic criteria. CONCLUSIONS: Results provide first-time quantitative data including specific evidence about losses to motor function and long-term compromises to work status. Results demonstrate that the ongoing impact of one episode of CRPS on limb function and work status is relatively high. SIGNIFICANCE: This review provides first-time clarity in relation to outcomes of limb function and work status associated with an episode of CRPS, beyond 12 months from onset. Results demonstrate that the long-term impact of an episode of CRPS on these outcomes is much larger than previously described, and thus also illustrates how the wider health economic impact of CRPS is not yet fully understood. We additionally highlight the need for future research that identifies long-term predictors, and treatments that can foster good functional and occupational recovery.

Mechanistically informed non-invasive peripheral nerve stimulation for peripheral neuropathic pain: a randomised double-blind sham-controlled trial.

BACKGROUND: Induction of long-term synaptic depression (LTD) is proposed as a treatment mechanism for chronic pain but remains untested in clinical populations. Two interlinked studies; (1) A patient-assessor blinded, randomised, sham-controlled clinical trial and (2) an open-label mechanistic study, sought to examine therapeutic LTD for persons with chronic peripheral nerve injury pain. METHODS: (1) Patients were randomised using a concealed, computer-generated schedule to either active or sham non-invasive low-frequency nerve stimulation (LFS), for 3 months (minimum 10 min/day). The primary outcome was average pain intensity (0-10 Likert scale) recorded over 1 week, at 3 months, compared between study groups. (2) On trial completion, consenting subjects entered a mechanistic study assessing somatosensory changes in response to LFS. RESULTS: (1) 76 patients were randomised (38 per group), with 65 (31 active, 34 sham) included in the intention to treat analysis. The primary outcome was not significant, pain scores were 0.3 units lower in active group (95% CI - 1.0, 0.3; p = 0.30) giving an effect size of 0.19 (Cohen's D). Two non-device related serious adverse events were reported. (2) In the mechanistic study (n = 19) primary outcomes of mechanical pain sensitivity (p = 0.006) and dynamic mechanical allodynia (p = 0.043) significantly improved indicating reduced mechanical hyperalgesia. CONCLUSIONS: Results from the RCT failed to reach significance. Results from the mechanistic study provide new evidence for effective induction of LTD in a clinical population. Taken together results add to mechanistic understanding of LTD and help inform future study design and approaches to treatment. Trial registration ISRCTN53432663.

A randomised, patient-assessor blinded, sham-controlled trial of external non-invasive peripheral nerve stimulation for chronic neuropathic pain following peripheral nerve injury (EN-PENS trial): study protocol for a randomised controlled trial.

BACKGROUND: Eight percent of people in the UK are estimated to have persistent (chronic) neuropathic pain, and for many there is no effective treatment. Medications are the most common first-line treatment but often have limited benefit or adverse events. Surgical treatments, such as spinal cord stimulation, are then often considered. External non-invasive peripheral nerve stimulation (EN-PENS) is a form of electrical stimulation that involves placing a pen-shaped electrode onto the skin, which can be easily self-administered by patients. Observational studies suggest that EN-PENS may relieve pain for people with localised neuropathic pain; however, there is currently no evidence from controlled trials to confirm the efficacy and confidently determine the effect size for patients with longstanding neuropathic pain. METHODS: EN-PENS is a single-site, blinded, randomised controlled parallel-group superiority add-on trial with a 1:1 allocation ratio, designed to evaluate the efficacy of treatment versus control treatment in 76 patients with longstanding neuropathic pain following peripheral nerve injury. Patients with moderate to -severe neuropathic pain following peripheral nerve injury will be randomised to receive either the active or control treatment, followed by an optional treatment extension or treatment switch to the alternative treatment arm. The primary outcome is average 24-h pain intensity recorded on an 11-point (0-10) numerical rating scale, averaged over the last 7 days of treatment. DISCUSSION: Study results will be used to inform potential treatment efficacy and cost-effectiveness of EN-PENS for this population group. TRIAL REGISTRATION: ISRCTN53432663 . Registered on 7 July 2016.

Long-Term Treatment of Chronic Neuropathic Pain Using External Noninvasive External Peripheral Nerve Stimulation in Five Patients.

BACKGROUND: External noninvasive peripheral nerve stimulation (EN-PNS) is a neuromodulation technique in which a low-frequency electrical stimulation is applied via a ball-shaped electrode that is placed directly onto the skin. OBJECTIVES: To examine how this modality is being used in the long term, by patients with chronic neuropathic pain who had responded to this treatment in a short-term trial. MATERIALS AND METHODS: All patients with a diagnosis of neuropathic pain who had obtained a machine for continued long-term use (via special funding requests), following a successful trial between 2009 and 2012 were contacted. A successful trial was considered as >50% pain reduction, duration of any beneficial treatment effect ≥12 hours, and improvements to function/reduced medication use. Data were collected from case notes and a telephone interview. RESULTS: Thirteen trials were recorded successful, out of 21 conducted. Eleven individual funding applications were made, of which seven were successful. Five patients were contactable. All reported continued stimulator use at follow-up (average = 3.5 years) and ongoing pain relief associated with treatment. Pain intensities (numerical rating scale 0-10) had reduced in all five cases when baseline scores were compared with follow-up scores; average pain 5.6-3.5 and worst pain 8.6-4.8. All patients reported a reduction in frequency of pain flare-ups during device use. CONCLUSION: Patients reported EN-PNS to provide ongoing benefit at long-term follow-up. Further prospective investigations are justified.

The development and delivery of a female chronic pelvic pain management programme: a specialised interdisciplinary approach.

CONTEXT/BACKGROUND: Chronic pelvic pain (CPP) is a physically and psychologically debilitating condition. European Association of Urology (EAU) Guidelines (2013) and Royal College of Obstetricians and Gynaecologists (RCOG) guidelines (2012) place strong emphasis upon multi-speciality assessment and liaison, as well as interdisciplinary assessment and intervention in reference to the management of CPP. OBJECTIVES: The aim was to introduce and describe the development and delivery of an interdisciplinary pain management programme (PMP), at a Specialised Pain Management Centre in Liverpool, United Kingdom, for women diagnosed with CPP. METHOD: The format and content of the CPP PMP at The Walton Centre, Liverpool, is described and the preliminary results from the CPP PMP are presented. RESULTS: Preliminary data suggest that outcomes on the specialised CPP PMP indicate that patients are able to make clinically important change across a range of outcome measures. Moreover, these results compare favourably to the established PMP for generalised chronic pain when comparing clinically significant outcomes with the Walton Centre's (a tertiary-level pain management centre) 2013 PMP Audit document. Patients attending the CPP PMP positively appraised the PMP and felt it was useful and supportive to be in a group dedicated to CPP. CONCLUSIONS: This article presents some preliminary results that suggest there is value in delivering a specialised multidisciplinary PMP for this group. There is a clear need for further clinical research into the effectiveness of similar interventions for CPP, including the early identification of those CPP patients who may benefit from both multi-specialty and interdisciplinary management.

External Noninvasive Peripheral Nerve Stimulation Treatment of Neuropathic Pain: A Prospective Audit.

BACKGROUND: Peripheral nerve stimulation (PNS) is a neuromodulation technique in which electrical current is applied to the peripheral nerves to ameliorate chronic pain through preferential activation of myelinated fibres, inducing long-term depression of synaptic efficacy. External noninvasive peripheral nerve stimulation (EN-PNS) is a novel and simple form of PNS that involves stimulation via an external nerve-mapping probe that is placed on the skin and connected to a power source. OBJECTIVES: We aimed to assess the clinical utility of EN-PNS in patients with refractory neuropathic pains referred to a tertiary pain treatment center. METHODS: We undertook a prospective audit of EN-PNS. Patients with a diagnosis of either complex regional pain syndrome or neuropathic pain after peripheral nerve injury who met inclusion criteria were included. Participants completed three stages of the audit: stage 1, six weekly outpatient treatment sessions; stage 2, six-week equipment home loan; stage 3, six weeks of no EN-PNS treatment. The primary outcome was the average post-treatment instantaneous pain intensity during the last week in stage 2 compared with baseline (11-point numerical rating scale). RESULTS: EN-PNS provided significant short-term pain relief (n = 20 patients, average reduction of 2.8 numerical rating scale points, 95% CI 1.6-4.0, p < 0.001, intention-to-treat analysis). Eight patients (40%) improved in several outcome parameters ("responders"), including quality of life and function. CONCLUSION: In this first prospective report on the use of EN-PNS in neuropathic pain, this technology provided significant clinical benefit for some patients. Controlled studies are required to confirm our results and the place of EN-PNS in future neuromodulation treatment algorithms. Given the refractory nature of these conditions, these results are encouraging.